Deployment Strategies on PCE-based Inter-AS LSP Path Computation

Nowadays, multiprotocol label switching (MPLS) is used inside autonomous systems (ASs) for virtual private networks (VPNs) or traffic engineering (TE) purposes. The need for inter-AS label switched paths (LSPs) is growing, as carries and service providers (SPs) build multi-services network based on MPLS-enabled infrastructures. It becomes a key issue to extend the ability to deliver these services across SP domain boundaries. In this paper, we discuss the requirements for the inter-AS MPLS-TE. We also summarize the path computation element (PCE) architecture. Then we explain the approaches of using a PCE for the LSP path computation in inter-AS MPLS-TE. To illustrate our point, we compare two LSP path computation techniques